Why not use PVC tubing or Sonotube for mid enclosures, mounting the driver in one end and capping the other? With the proper size tubing, you get no baffle. Heck, you could even use progessively smaller tubing, mounting each inside the other, to taper the tube similar to how B&W does it.

I know I am not a genious, and someone else has already thought of this or else there is good engineering why it won't work.

Acoustically, you will still have a baffle of the size of the membrane, so you will not get rid of the baffle step in this way, if that was what you intended. But sure, it will be smaller than *any* other baffle that you can mount the driver in.